$(15$ points$)$ A $1-$in$.16$ BWG copper tube has its outside surface maintained at $240F.$ If this tube is placed in still air at $60F,$ what heat flux will be achieved if the tube is oriented:

a$)$ Horizontally?

b$)$ Vertically?

Note: Use the natural convection relations for the Nusselt Number given in Chapter $20$ for varied geometries to find $\text{'}h\text{'}$ for both conditions and then find heat flux. Use Appendix I to find fluid properties such as $k,\frac{g**{}^2}{{}^2},$ Pr$,$ etc. at film temperature